如何降低 Realtek 以太网设备的功耗？

我有一台装有 Debian 12 的笔记本电脑，根据 powertop 显示，Realtek 以太网控制器的功耗约为 10W：

Power est.              Usage       Events/s    Category       Description
  11.9 W      0.0 pkts/s                Device         Network interface: enp4s0 (r8168)
 92.7 mW     97.5 ms/s     191.0        Process        [PID 35665] /usr/lib/xorg/Xorg vt3 -displayfd 3 -auth /run/user/1000/gdm/Xauthority -nolisten tcp -background none -noreset -ke
 84.2 mW     88.6 ms/s      15.4        Process        [PID 36881] /usr/libexec/gnome-terminal-server

即使设备已关闭，仍会消耗电力：

$ ip a
2: enp4s0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc fq_codel state DOWN group default qlen 1000
    link/ether a8:3e:43:5d:a5:1a brd ff:ff:ff:ff:ff:ff

有什么方法可以完全禁用该设备或至少降低功耗？

一些额外的诊断：

$ lspci | grep -i "Ethernet"
04:00.0 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL8111/8168/8411 PCI Express Gigabit Ethernet Controller (rev 15)

$ nmcli device show enp4s0
GENERAL.DEVICE:                         enp4s0
GENERAL.TYPE:                           ethernet
GENERAL.HWADDR:                         A8:3E:43:5D:A5:1A
GENERAL.MTU:                            1500
GENERAL.STATE:                          20 (unavailable)
GENERAL.CONNECTION:                     --
GENERAL.CON-PATH:                       --
WIRED-PROPERTIES.CARRIER:               off
IP4.GATEWAY:                            --
IP6.GATEWAY:                            --